Possibly the best comic book movie to date. I am a little cautious about the comment above, as I have not seen Batman begins, but this movie certainly beat all of the earlier super-hero movies I have seen, and several that came after. The success of this movie came from the focus on human relationships and in particular on the story of Rogue as she comes to terms with her, rather scary, power, her place in society and her relationships with others. Because Singer took the time to build up our rapport for Rogue, the later events, where she comes into danger and the rest of the team come together to support her, have much more emotional resonance than I found in any of the Superman/Spiderman movies.
Of course it also delivers all of the action and effects that we expect in a superhero movie, along with an engaging villain or two, and a devious plot that only becomes clear as the movie progresses.
A very solid opening round for the X-Men franchise, that unfortunately was not followed up on with the same flair.